Core-pressing apparatus.



77362265696; fiii Azzzfenl ord THE NORRIS PETERS CO., WAEHINGIUN, n. c

PATENTED SEPT. 24, 1907. P. ERIKSSON & S. P. NIELSEN. CORE PRBSSINGAPPARATUS. APPLICATION TILED MAY 14, 1906.

UNITED STATES PATENT OFFICE.

PETTER ERIKSSON, OF LUND, AND SGREN PETER NIELSEN, OF VESTERAS, SWEDEN.

CORE-PRESSING APPARATUS.

Specification of Letters Patent.

Patented Sept. 24, 1907,

Application filedMey 14,1906. Serial No. 316,788.

To all whom it may concern:

Be it known that we, PETTER Enikssomresiding at Lund, and SGREN PETERNIELSEN, residing at Vesteras, both in Sweden, and subjects of the Kingof Sweden, have invented certain new and useful Improvements inSo-Called Core-Pressing Apparatuses for Producing Cores for CastingPurposes; and we do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings, and to letters orfigures of reference marked thereon, which form a part of thisspecification.

In a number of apparatus hitherto used for making cores for castingpurposes the core-sand is packed by hand into a core-box, whereafter thecore is either pushed out by a piston or else the box is made in partsand divided lengthwise into two halves, so that it can be opened and thecore taken out. Neither of these methods give a perfect core, the formercase because the core on being forced out has a part of the corecompacted too hard, and in the latter case because it does not leave thecore perfectly even on the surface. There are also apparatus whichautomatically, that is, by means of an endless screw, pack thecore-material and continuously deliver the complete cores, but theseapparatus are very complicated, can only operate with a core-materialconsisting of certain compounds which greatly increase the cost of themanufacturing and require besides a great consumption of power and areexposed to much wear.

The present invention enables the manufacture of continuous cores ofgreat accuracy and of uniform compactness throughout at a relativelygreat speed with small expenditure of power.

The invention is illustrated on the accompanying drawings in which likeparts are similarly designated.

' Figures 1 and 2 show cross-sections of the device taken respectivelyon the lines l1 and 22 of Fig. 3, and Fig. 3 a longitudinal sectionpartly in elevation of the machine.

The core-sand, suitably moistened, is fed to the feedbox a from areservoir not shown in the drawings. In the lower part of the feed-boxthe plunger or core forming-device proper is mounted. This latterconsists at a pressure-piston or plunger b passing through twooppositely situated openings in the side walls of the feeding-box andreceives an axial reciprocation. The plunger is, in order to formvent-holes through the cores, provided with a central hole, into whichis put a pin or rod 0 projecting somewhat beyond the compacting end oractive face of the plunger. On the outside of the feedbox and inalinement with the plunger is placed a coremold d, into which thecore-sand, at each forward movement of the plunger, is automaticallyforced and packed, the finished core being at the same time forced outin the shape of a cylinder through the outer end of the core mold, sothat it will be projected in front thereof and rest on a plate placedadjacent the exit end'of the mold, said plate not being shown.

In order that the sand may not be unevenly packed, which would be thecase in using a plane plunger end, this latter is provided with two ormore obliquely projecting pins e. The object of these is that when theplunger is drawn back, from the core mold to tear up or break down theinner end of the core in the mold, so that the plunger when pressinganother charge of sand into the mold at the next stroke will not packthe same against a hard, smooth or plane surface. Unless this is donethe finished core would not have sufiicient cohesion but would at theleast touch fall in pieces with plane fractures between the successivecharges of sand. In order to make the core perfectly uniform, the sandfed to the plunger must be uniform and the feeding even so that theplunger at each stroke forces the same quantity of sand into the mold.The feeding of the sand is therefore effected by a suitable feedingdevice, preferably of the type, shown in Fig. 3. Above plunger b andsomewhat to the side thereof there is mounted a shaft f parallel to theplunger, said shaft f being provided with a series of arms and rods g,which by means of the shaft receive a swinging motion and thereby mixthe sand on its way downward while a plate or the like h, mounted on oneof the arms g, at each reciprocation of the plunger, holds a suflicientquantity of sand to the plunger end. Plunger b and shaft f suitablyreceive their motion from any suitable gearing device driven by arotating shaft that is actuated by hand or in any other suitable way.

By means of the herein described device it is obvious that not onlycylindrical cores of any diameter whatever may be produced but alsocores of any other crosssection whatever.

For different dimensions the core mold and the plunger need only beexchanged, the cross-section of the latter always being somewhat smallerthan that of the i core. The vent hole will obviously always be exactlyin the center of the core.

We claim:

1. In a core forming machine the combination with a receptacle for corematerial having openings therethrough, a core mold adjacent one of theopenings, a reciprocable plunger in the receptacle to force materialinto the mold, in combination with means to break up the end of the coreadjacent the plunger as the plunger is withdrawn from the mold.

2. In a. machine such as described, the combination with the coreforming plunger and a core mold, of means on the end of the plunger tobreak up the end of the core adjacent the plunger as the latter iswithdrawn from the mold.

3. In a machine such as described, the combination with the core formingplunger and a core mold of inclined pins on the end of the plunger tobreak up the end of the core as the plunger is Withdrawn from the mold.

In testimony, that we claim the foregoing as our invention, we havesigned our names in presence of two subscribing witnesses.

PETTER ERIKSSON.

sdnnN PETER NIELSEN.

Witnesses to the signature of Mr. Eriksson:

M. TnNznR, E. A. LINDEGBEN.

Witnesses to the signature of Mr. Nielsen: i

CHRISTIAN NILSSON, p P. F. BLOMKVIST.

